LONDON - Troubled British singer Amy Winehouse pleaded not guilty Tuesday to assaulting a woman at a charity ball last year - and appeared in sunnier form than in recent times.

The 25-year-old "Back to Black" songstress smiled for photographers as she arrived, sun-tanned from a recent Caribbean holiday and in a summery flowered dress, at City of Westminster Magistrates' Court in London.

Asked how she was feeling, she said: "I'm all right, thanks." She is accused of common assault for allegedly beating a woman, Sherene Flash, in an incident in Berkeley Square, central London, last September 26.

Asked how she pleaded, she replied: "Not guilty."

Her lawyer apologised to judge Timothy Workman for her late arrival, saying she had left home at 8.15 am but had been delayed. "I do apologise to the court on her behalf," said lawyer Mark Haslam.

Asked to give her full name, Winehouse replied in a confident voice: "Amy Jade Civil" - from her husband Blake Fielder-Civil, whose lawyer announced in January that he was seeking a divorce on grounds of her adultery.

Winehouse has struggled with alcohol and drug problems, and been pictured in less than flattering circumstances.

In court she listened to proceedings, albeit while fidgeting in her seat and adjusting the straps on her dress. The case was adjourned until July 23.